/*
* Copyright 2008-2009 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Sun designates this
* particular file as subject to the "Classpath" exception as provided
* by Sun in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
package com.sun.awt;
import java.awt.*;
import sun.awt.AWTAccessor;
import sun.awt.SunToolkit;
/**
* A collection of utility methods for AWT.
*
* The functionality provided by the static methods of the class includes:
* <ul>
* <li>Setting shapes on top-level windows
* <li>Setting a constant alpha value for each pixel of a top-level window
* <li>Making a window non-opaque, after that it paints only explicitly
* painted pixels on the screen, with arbitrary alpha values for every pixel.
* <li>Setting a 'mixing-cutout' shape for a component.
* </ul>
* <p>
* A "top-level window" is an instance of the {@code Window} class (or its
* descendant, such as {@code JFrame}).
* <p>
* Some of the mentioned features may not be supported by the native platform.
* To determine whether a particular feature is supported, the user must use
* the {@code isTranslucencySupported()} method of the class passing a desired
* translucency kind (a member of the {@code Translucency} enum) as an
* argument.
* <p>
* The per-pixel alpha feature also requires the user to create her/his
* windows using a translucency-capable graphics configuration.
* The {@code isTranslucencyCapable()} method must
* be used to verify whether any given GraphicsConfiguration supports
* the trasnlcency effects.
* <p>
* <b>WARNING</b>: This class is an implementation detail and only meant
* for limited use outside of the core platform. This API may change
* drastically between update release, and it may even be
* removed or be moved in some other package(s)/class(es).
*/
public final class AWTUtilities {
/**
* The AWTUtilities class should not be instantiated
*/
private AWTUtilities() {
}
/** Kinds of translucency supported by the underlying system.
* @see #isTranslucencySupported
*/
public static enum Translucency {
/**
* Represents support in the underlying system for windows each pixel
* of which is guaranteed to be either completely opaque, with
* an alpha value of 1.0, or completely transparent, with an alpha
* value of 0.0.
*/
PERPIXEL_TRANSPARENT,
/**
* Represents support in the underlying system for windows all of
* the pixels of which have the same alpha value between or including
* 0.0 and 1.0.
*/
TRANSLUCENT,
/**
* Represents support in the underlying system for windows that
* contain or might contain pixels with arbitrary alpha values
* between and including 0.0 and 1.0.
*/
PERPIXEL_TRANSLUCENT;
}
/**
* Returns whether the given level of translucency is supported by
* the underlying system.
*
* Note that this method may sometimes return the value
* indicating that the particular level is supported, but
* the native windowing system may still not support the
* given level of translucency (due to the bugs in
* the windowing system).
*
* @param translucencyKind a kind of translucency support
* (either PERPIXEL_TRANSPARENT,
* TRANSLUCENT, or PERPIXEL_TRANSLUCENT)
* @return whether the given translucency kind is supported
*/
public static boolean isTranslucencySupported(Translucency translucencyKind) {
switch (translucencyKind) {
case PERPIXEL_TRANSPARENT:
return isWindowShapingSupported();
case TRANSLUCENT:
return isWindowOpacitySupported();
case PERPIXEL_TRANSLUCENT:
return isWindowTranslucencySupported();
}
return false;
}
/**
* Returns whether the windowing system supports changing the opacity
* value of top-level windows.
* Note that this method may sometimes return true, but the native
* windowing system may still not support the concept of
* translucency (due to the bugs in the windowing system).
*/
private static boolean isWindowOpacitySupported() {
Toolkit curToolkit = Toolkit.getDefaultToolkit();
if (!(curToolkit instanceof SunToolkit)) {
return false;
}
return ((SunToolkit)curToolkit).isWindowOpacitySupported();
}
/**
* Set the opacity of the window. The opacity is at the range [0..1].
* Note that setting the opacity level of 0 may or may not disable
* the mouse event handling on this window. This is
* a platform-dependent behavior.
*
* In order for this method to enable the translucency effect,
* the isTranslucencySupported() method should indicate that the
* TRANSLUCENT level of translucency is supported.
*
* <p>Also note that the window must not be in the full-screen mode
* when setting the opacity value < 1.0f. Otherwise
* the IllegalArgumentException is thrown.
*
* @param window the window to set the opacity level to
* @param opacity the opacity level to set to the window
* @throws NullPointerException if the window argument is null
* @throws IllegalArgumentException if the opacity is out of
* the range [0..1]
* @throws IllegalArgumentException if the window is in full screen mode,
* and the opacity is less than 1.0f
* @throws UnsupportedOperationException if the TRANSLUCENT translucency
* kind is not supported
*/
public static void setWindowOpacity(Window window, float opacity) {
if (window == null) {
throw new NullPointerException(
"The window argument should not be null.");
}
AWTAccessor.getWindowAccessor().setOpacity(window, opacity);
}
/**
* Get the opacity of the window. If the opacity has not
* yet being set, this method returns 1.0.
*
* @param window the window to get the opacity level from
* @throws NullPointerException if the window argument is null
*/
public static float getWindowOpacity(Window window) {
if (window == null) {
throw new NullPointerException(
"The window argument should not be null.");
}
return AWTAccessor.getWindowAccessor().getOpacity(window);
}
/**
* Returns whether the windowing system supports changing the shape
* of top-level windows.
* Note that this method may sometimes return true, but the native
* windowing system may still not support the concept of
* shaping (due to the bugs in the windowing system).
*/
public static boolean isWindowShapingSupported() {
Toolkit curToolkit = Toolkit.getDefaultToolkit();
if (!(curToolkit instanceof SunToolkit)) {
return false;
}
return ((SunToolkit)curToolkit).isWindowShapingSupported();
}
/**
* Returns an object that implements the Shape interface and represents
* the shape previously set with the call to the setWindowShape() method.
* If no shape has been set yet, or the shape has been reset to null,
* this method returns null.
*
* @param window the window to get the shape from
* @return the current shape of the window
* @throws NullPointerException if the window argument is null
*/
public static Shape getWindowShape(Window window) {
if (window == null) {
throw new NullPointerException(
"The window argument should not be null.");
}
return AWTAccessor.getWindowAccessor().getShape(window);
}
/**
* Sets a shape for the given window.
* If the shape argument is null, this methods restores
* the default shape making the window rectangular.
* <p>Note that in order to set a shape, the window must be undecorated.
* If the window is decorated, this method ignores the {@code shape}
* argument and resets the shape to null.
* <p>Also note that the window must not be in the full-screen mode
* when setting a non-null shape. Otherwise the IllegalArgumentException
* is thrown.
* <p>Depending on the platform, the method may return without
* effecting the shape of the window if the window has a non-null warning
* string ({@link Window#getWarningString()}). In this case the passed
* shape object is ignored.
*
* @param window the window to set the shape to
* @param shape the shape to set to the window
* @throws NullPointerException if the window argument is null
* @throws IllegalArgumentException if the window is in full screen mode,
* and the shape is not null
* @throws UnsupportedOperationException if the PERPIXEL_TRANSPARENT
* translucency kind is not supported
*/
public static void setWindowShape(Window window, Shape shape) {
if (window == null) {
throw new NullPointerException(
"The window argument should not be null.");
}
AWTAccessor.getWindowAccessor().setShape(window, shape);
}
private static boolean isWindowTranslucencySupported() {
/*
* Per-pixel alpha is supported if all the conditions are TRUE:
* 1. The toolkit is a sort of SunToolkit
* 2. The toolkit supports translucency in general
* (isWindowTranslucencySupported())
* 3. There's at least one translucency-capable
* GraphicsConfiguration
*/
Toolkit curToolkit = Toolkit.getDefaultToolkit();
if (!(curToolkit instanceof SunToolkit)) {
return false;
}
if (!((SunToolkit)curToolkit).isWindowTranslucencySupported()) {
return false;
}
GraphicsEnvironment env =
GraphicsEnvironment.getLocalGraphicsEnvironment();
// If the default GC supports translucency return true.
// It is important to optimize the verification this way,
// see CR 6661196 for more details.
if (isTranslucencyCapable(env.getDefaultScreenDevice()
.getDefaultConfiguration()))
{
return true;
}
// ... otherwise iterate through all the GCs.
GraphicsDevice[] devices = env.getScreenDevices();
for (int i = 0; i < devices.length; i++) {
GraphicsConfiguration[] configs = devices[i].getConfigurations();
for (int j = 0; j < configs.length; j++) {
if (isTranslucencyCapable(configs[j])) {
return true;
}
}
}
return false;
}
/**
* Enables the per-pixel alpha support for the given window.
* Once the window becomes non-opaque (the isOpaque is set to false),
* the drawing sub-system is starting to respect the alpha value of each
* separate pixel. If a pixel gets painted with alpha color component
* equal to zero, it becomes visually transparent, if the alpha of the
* pixel is equal to 255, the pixel is fully opaque. Interim values
* of the alpha color component make the pixel semi-transparent (i.e.
* translucent).
* <p>Note that in order for the window to support the per-pixel alpha
* mode, the window must be created using the GraphicsConfiguration
* for which the {@link #isTranslucencyCapable}
* method returns true.
* <p>Also note that some native systems enable the per-pixel translucency
* mode for any window created using the translucency-compatible
* graphics configuration. However, it is highly recommended to always
* invoke the setWindowOpaque() method for these windows, at least for
* the sake of cross-platform compatibility reasons.
* <p>Also note that the window must not be in the full-screen mode
* when making it non-opaque. Otherwise the IllegalArgumentException
* is thrown.
* <p>If the window is a {@code Frame} or a {@code Dialog}, the window must
* be undecorated prior to enabling the per-pixel translucency effect (see
* {@link Frame#setUndecorated()} and/or {@link Dialog#setUndecorated()}).
* If the window becomes decorated through a subsequent call to the
* corresponding {@code setUndecorated()} method, the per-pixel
* translucency effect will be disabled and the opaque property reset to
* {@code true}.
* <p>Depending on the platform, the method may return without
* effecting the opaque property of the window if the window has a non-null
* warning string ({@link Window#getWarningString()}). In this case
* the passed 'isOpaque' value is ignored.
*
* @param window the window to set the shape to
* @param isOpaque whether the window must be opaque (true),
* or translucent (false)
* @throws NullPointerException if the window argument is null
* @throws IllegalArgumentException if the window uses
* a GraphicsConfiguration for which the
* {@code isTranslucencyCapable()}
* method returns false
* @throws IllegalArgumentException if the window is in full screen mode,
* and the isOpaque is false
* @throws IllegalArgumentException if the window is decorated and the
* isOpaque argument is {@code false}.
* @throws UnsupportedOperationException if the PERPIXEL_TRANSLUCENT
* translucency kind is not supported
*/
public static void setWindowOpaque(Window window, boolean isOpaque) {
if (window == null) {
throw new NullPointerException(
"The window argument should not be null.");
}
if (!isOpaque && !isTranslucencySupported(Translucency.PERPIXEL_TRANSLUCENT)) {
throw new UnsupportedOperationException(
"The PERPIXEL_TRANSLUCENT translucency kind is not supported");
}
AWTAccessor.getWindowAccessor().setOpaque(window, isOpaque);
}
/**
* Returns whether the window is opaque or translucent.
*
* @param window the window to set the shape to
* @return whether the window is currently opaque (true)
* or translucent (false)
* @throws NullPointerException if the window argument is null
*/
public static boolean isWindowOpaque(Window window) {
if (window == null) {
throw new NullPointerException(
"The window argument should not be null.");
}
return window.isOpaque();
}
/**
* Verifies whether a given GraphicsConfiguration supports
* the PERPIXEL_TRANSLUCENT kind of translucency.
* All windows that are intended to be used with the {@link #setWindowOpaque}
* method must be created using a GraphicsConfiguration for which this method
* returns true.
* <p>Note that some native systems enable the per-pixel translucency
* mode for any window created using a translucency-capable
* graphics configuration. However, it is highly recommended to always
* invoke the setWindowOpaque() method for these windows, at least
* for the sake of cross-platform compatibility reasons.
*
* @param gc GraphicsConfiguration
* @throws NullPointerException if the gc argument is null
* @return whether the given GraphicsConfiguration supports
* the translucency effects.
*/
public static boolean isTranslucencyCapable(GraphicsConfiguration gc) {
if (gc == null) {
throw new NullPointerException("The gc argument should not be null");
}
/*
return gc.isTranslucencyCapable();
*/
Toolkit curToolkit = Toolkit.getDefaultToolkit();
if (!(curToolkit instanceof SunToolkit)) {
return false;
}
return ((SunToolkit)curToolkit).isTranslucencyCapable(gc);
}
/**
* Sets a 'mixing-cutout' shape for the given component.
*
* By default a lightweight component is treated as an opaque rectangle for
* the purposes of the Heavyweight/Lightweight Components Mixing feature.
* This method enables developers to set an arbitrary shape to be cut out
* from heavyweight components positioned underneath the lightweight
* component in the z-order.
* <p>
* The {@code shape} argument may have the following values:
* <ul>
* <li>{@code null} - reverts the default cutout shape (the rectangle equal
* to the component's {@code getBounds()})
* <li><i>empty-shape</i> - does not cut out anything from heavyweight
* components. This makes the given lightweight component effectively
* transparent. Note that descendants of the lightweight component still
* affect the shapes of heavyweight components. An example of an
* <i>empty-shape</i> is {@code new Rectangle()}.
* <li><i>non-empty-shape</i> - the given shape will be cut out from
* heavyweight components.
* </ul>
* <p>
* The most common example when the 'mixing-cutout' shape is needed is a
* glass pane component. The {@link JRootPane#setGlassPane()} method
* automatically sets the <i>empty-shape</i> as the 'mixing-cutout' shape
* for the given glass pane component. If a developer needs some other
* 'mixing-cutout' shape for the glass pane (which is rare), this must be
* changed manually after installing the glass pane to the root pane.
* <p>
* Note that the 'mixing-cutout' shape neither affects painting, nor the
* mouse events handling for the given component. It is used exclusively
* for the purposes of the Heavyweight/Lightweight Components Mixing
* feature.
*
* @param component the component that needs non-default
* 'mixing-cutout' shape
* @param shape the new 'mixing-cutout' shape
* @throws NullPointerException if the component argument is {@code null}
*/
public static void setComponentMixingCutoutShape(Component component,
Shape shape)
{
if (component == null) {
throw new NullPointerException(
"The component argument should not be null.");
}
AWTAccessor.getComponentAccessor().setMixingCutoutShape(component,
shape);
}
}